Telecommunications Essentials

Chapter 10

Next-Generation Networks

Broadband Growth

• Information demand• Wideband applications

• Video streaming• Networked gaming• E-commerce

• Convergence• Shift to machine-to-machine communication

• More microprocessors than people• Bandwidth cost is dropping (more slowly now)

Bandwidth Growth

• The Bandwidth Report• Wireless is expected to dominate• China, India, Russia expect biggest increase• Increases productivity (compared to dialup)

Business Class Services

• eCommerce• VPNs• Video conferencing• Collaboration

Broadband Applications

• Entertainment• Internet video/movies/TV/gaming

• Education• Rich-media content delivery• Wireless campus

• Research Labs• LHC, Grid Computing,

• Health Care• Teleworking• National Security

Digital Video

• DTV• Reduced bandwidth requirements due to compression• Nearly immune to interference• Can become interactive

DTV Standards

• Convergence of broadcasting & computing• Next generation of TV• New features

• Multiple –windows• Interactive viewing options• 6x improvement in video quality• CD quality sound

• May have to compete with webTV

International Standards

• ATSC - Advanced Television Systems Committee• Adopted by Canada & U.S.• U.S. Analog switch-off date: February 17, 2009• Canada: Aug. 31, 2011

• DVB – Digital Video Broadcasting• Europe & Australia• Similar to ATSC except for audio compression &

transmission

ATSC DTV Standard

Vertical HorizontalAspect Ratio Frame Rate Scanning

HDTV 1080 1920 16:9 30, 24 progressive

1080 1920 16:9 60 interlaced

720 1280 16:9 60, 30, 24 progressive

DTV 480 704 4:3 60, 30, 24 progressive

480 640 4:3 60, 30, 24 progressive

SDTV 480 704 4:3 60 interlaced

480 640 4:3 60 interlaced

MPEG

• MPEG-1• Video CDs 1.5 Mbps• MP3 audio

• MPEG-2• DVD and DTV

• MPEG-4• Object based encoding• WMP, QuickTime

• MPEG-7• Multimedia content

• MPEG-21• Software libraries for production and delivery of content

MPEG-2 & Bandwidth

• DVD – 10.8 Mbps• HDTV – 20 Mbps, Blu-Ray• Video delivery requires:

• More sophisticated video compression• Fiber to the X• New generation of wireless equipment

Broadband Service Requirements

• High speed & capacity• Bandwidth on demand• Bandwidth reservation• Support isochronous traffic• Agnostic platforms• Support for unicasting & multicasting• QoS

Technology Enablers

• Erbium-doped fiber amplifiers• DWDM• Optical add/drop multiplexers, cross-

connect switches, & routers• HFC, FTTC, FTTH• Broadband wireless & satellite• Intelligent networks, softswitches, &

media gateways

Delay & Jitter

• ITU recommendations• Maximum setup delay: 150 mSec• Packet loss: < 1%

• Presently it is up to 40%

• Round trip latency: < 80 mSec• Presently it is up to 1000 mSec

Next-Generation Networks

IP

• IP – a LAN protocol• Connectionless• Discards packets when congested• Traditional routers cannot deliver service quality• VoIP & streaming media require low latency & jitter

(voice compression 30 – 50 mSec)• Increase Bandwidth

• Short term solution• IP Switching

• Long term solution

IP Switching

• Connection oriented• Routes the first packet• Switches the other packets• Replaces Layer 3 hops with Layer 2 switching

• Enables:• Voice, video, & graphics applications

• Objectives• Scale economically• Improve QoS

• Limitation• Not enough QoS control

IP Multimedia System

CSCF – Call Session Control FunctionHSS – Home Subscriber Services

Designed for IPv6 mobile networksAdapted for IPv4 fixed services

Ericsson Slide Show

ATM

• A WAN technique• Connection oriented• Provides real-time traffic management• Supports CoS and QoS provisioning• Supports voice, IP, frame relay, X.25 etc.

• Limitation• Scaling problems• A virtual circuit is required between every IP router

• Possible solutions• Abandon a full-mesh architecture• Migrate to MPLS

IP vs. ATM

+ -

IP Pervasive at the desktop

No QoS

ATM CoS & QoS High cell overhead

Terabit Switch Routers• Proprietary• Backbone platform• Article by Amit Singhal • Single Chip Terabit Switch• GlimmerGlass

Today’s Networks

Facilities for each service category have been separately engineered

Current Broadband Architecture

• Current systems use overlay networks• Access and transport functions are separated• Adds capacity & service without disruption

• Problem• High O&M costs• New services require new provision

management & troubleshooting systems

Multiservice Network

Three Tier Architecture

• Outer – Broadband Access• Customer service

• Middle – Intelligent Edge• Protocol and data service integration

• Inner – High-Speed Core• Core switches

Broadband Access

• Provides the end-user with a broadband link• Class 5 local exchange• DLC• DSLAM• IAD• Remote access servers

Intelligent Edge

• Establishes QoS, authentication, authorization etc.

• Equipment type:• MSPP• VoIP, Media, & Trunking Gateways• ATM switches• IP routers & switches

Next-Gen Network Edge

Multipurpose Switch

Intelligent Edge Functions

• Broadband access• Adaptation of native traffic• Data concentration• QoS mapping• Service provisioning• Encryption• Accounting• Address administration• The Edge is becoming more intelligent and the network

more dumb• A reversal of the traditional PSTN

High-Speed Core

• Scalable• Fast• Dumb

Softswitch

• A software-based distributed switching & control platform

• No industry-standard definition• China may be the first to develop an

interoperable switch• Ericsson

ATM Service Category (QoS)

• CBR- Constant bit rate• Highest class of service• Streaming media

• VBR – Variable bit rate• Highest class of data service• Adequate for real-time voice

• ABR – Available bit rate• LAN interconnect

• UBR – Unspecified bit rate• Text data, image transfer, messaging

IP Service Levels

• IntServ (Integrated Services)

• Bandwidth reservation• Internet virtual circuits• Three service classes

• Guaranteed Service• Controlled Load Service• Best-Effort Service

• DiffServ (Differentiated Services)

• A CoS (Class of Service) model• Prioritizes different data streams• Cannot specify traffic control parameters

MPLS (Multi Protocol Label Switching)

• Uses local labels to identify:• Traffic types• Path• Destination

• Supports bandwidth reservation• Operates at Layer 2• Supports tunneling• Issues between IETF and IP/MPLS Forum